Thermoviscous fluid flow in nonisothermal layer: structures, scales and correlations
Yu.M. Kulikov1, E.E. Son1
Joint Institute for High Temperatures RAS, Moscow, Russia
Keywords: термовязкая жидкость, Q-критерий, энстрофия, автокорреляционные функции скорости, взаимные корреляционные функции, шпильковидный вихрь, эйлеров коэффициент корреляции, длина корреляции, интегральный масштаб, скорость трения, единицы стенки, thermoviscosity, Q-criterion, enstrophy, velocity autocorrelation functions, cross-correlation functions, hairpin vortex, Eulerian correlation coefficient, correlation length, integral scale, friction velocity, Reynolds scaling
Abstract
The paper studies turbulent mixing in thermoviscous fluid flow in a 3D cubic domain which is extended periodically in two directions (X and Y). The flow turbulization develops under the impact of two-dimensional chaotic disturbances at mass average Reynolds number Re1 = 4704. The vortex field structure is discussed in terms of an isosurface of Q-criterion and local enstrophy zl. For the advanced stages of flow evolution, the study considers Eulerian correlation coefficients for velocity fluctuations (auto-correlation functions) and the cross-correlations of pressure and temperature. The Eulerian correlation coefficient is split for analysis of correlation characteristics in periodicity and wall-normal directions. The integral scale is evaluated depending on the distance to the walls. The flow analysis is performed in the terminology of viscous scale. The mesh resolution is evaluated for the flow regions corresponding to the logarithmic boundary layer and the near-wall thermal layers.
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